Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

060
FXUS63 KLOT 300507
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1107 PM CST Mon Dec 29 2025

.KEY MESSAGES...

- Light accumulating snow possible (50-70%) Tuesday
  afternoon/evening and again Wednesday afternoon/evening.

&&

.DISCUSSION...
Issued at 231 PM CST Mon Dec 29 2025

Very light snow/flurries have continued into this afternoon. A
dusting of new snow accumulation is possible in some areas but
with the continued gusty winds, areas of blowing snow will
remain possible this afternoon. Winds will be slowly diminishing
through this evening with gusts ending by late evening or early
overnight.

Some breaks in the clouds have developed today and the cloud
cover upstream is looking rather thin with continued breaks in
the clouds. Much of the guidance suggests this low cloud cover
will be scattering out overnight and perhaps be exiting the cwa
by daybreak. Have trended a bit more optimistic for cloud trends
tonight. Prior to any possible scattering, there will likely be
a continued chance of flurries this evening and added mention to
the forecast.

Attention then turns to two weak clipper systems. The first to
arrive Tuesday afternoon. This system has been in the models for
several days, but has slowly been trending further south and
much of the latest guidance now has light snow spreading/
developing across northern IL Tuesday afternoon and then ending
early Tuesday evening, mainly falling during the evening rush
hour. While confidence is only medium given the change in
trends, this looks to be a high pop/low qpf event and opted to
increase pops to likely. But snowfall amounts may only be a
dusting to a half inch or so, mainly along/north of I-80.

A second clipper system will move across the area Wednesday
afternoon into Wednesday evening. There has been a bit better
consistency between the models with this system (compared to the
Tuesday clipper). This also appears to be another high pop/low
qpf event and increased pops to likely. Timing also looks to be
during the Wednesday afternoon/evening rush hour. Snowfall
amounts may be more toward the one inch range. The snow looks
to end Wednesday evening and then another push of colder air is
expected into Thursday with wind chills Thursday morning
perhaps in the -5 to +5 range.

Temps look to moderate into the weekend, with perhaps temps
getting a little above normal. Blended guidance is mainly dry
which looks on track from this distance, but there does appear
to be another weak wave to move across the area Saturday night
or Sunday that could bring a brief period precip chances back
to the area. cms

&&

.AVIATION /06Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 1107 PM CST Mon Dec 29 2025

Key Aviation Messages for the current TAF period:

- Period of IFR snow late afternoon/evening tomorrow

Mid-high level cloudiness will quickly increase Tuesday morning
in advance of the next fast moving weather system expected to
impact the area tomorrow. Confidence in a period of light snow
has increased enough to go with a period of prevailing IFR snow
very late afternoon into the early-mid evening. Snow is expected
to end by mid-late evening with MVFR CIGS likely to through the
remainder of the night.

- Izzi

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory until 3 AM CST Tuesday for the IL
     nearshore waters.

     Small Craft Advisory until 3 PM CST Tuesday for the IN
     nearshore waters.

&&

$$

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